The angle of the outflow graft to the aorta can affect recirculation due to aortic insufficiency under left ventricular assist device support
The angle of the outflow graft to the aorta can affect recirculation due to aortic insufficiency under left ventricular assist device support
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DOI：
10.1007/s10047-018-1064-z
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发表时间：
2018-12-01
影响因子：
1.3
通讯作者：
Tatsumi, Eisuke
中科院分区：
文献类型：
--
作者：
Iizuka, Kei;Nishinaka, Tomohiro;Tatsumi, Eisuke
主动脉瓣关闭不全（AI）是连续流左心室辅助装置（LVAD）支持过程中的重要并发症。我们之前的临床研究表明，流出道移植物与主动脉之间的角度（O-A角）较大可能导致AI进展。本研究在急性动物实验模型上研究了在LVAD支持下，O-A角对AI血流动力学的影响。在7头小牛中安装LVAD，从LV心尖插入流入插管，并在升主动脉处缝合流出移植物。使用从LV心尖插入并放置在主动脉瓣处的临时下腔静脉滤器制作AI模型。通过连续β受体阻滞剂输注诱导心功能不全。在三个O-A角（45度、90度和135度）下，在三个AI水平（无、Sellers I-II AI和Sellers III-IV AI）上评价血流动力学值和心肌氧摄取率（O2 ER）。计算再循环率，定义为反流流量与LVAD输出的百分比。O-A角越大，体循环流量越小。O-A角越大，再循环率显著增加（Sellers III-IV AI在45度、90度和135度时分别为22%、23%和31%）。O-A角较大时冠状动脉血流减少（Sellers I-II AI在45度、90度和135度时分别为86、76和75 mL/min，Sellers III-IV AI在45度、90度和135度时分别为77、67和56 mL/min）。O2 ER倾向于随着O-A角的增大而增大（Sellers III-IV AI在45度、90度和135度时分别为40%、43%和49%）。较大的O-A角会增加AI引起的再循环，对LVAD-AI血流动力学和心肌氧代谢不利。
Aortic insufficiency (AI) is a crucial complication during continuous-flow left ventricular assist device (LVAD) support. Our previous clinical study suggested that a larger angle between the outflow graft and the aorta (O-A angle) could cause AI progression. This study examined the effect of the O-A angle on the hemodynamics of AI under LVAD support in an acute animal experimental model. An LVAD was installed in seven calves, with the inflow cannula inserted from the LV apex and with the outflow graft sutured at the ascending aorta. The AI model was made using a temporary inferior vena cava filter inserted from the LV apex and placed at the aortic valve. Cardiac dysfunction was induced by continuous beta-blocker infusion. Hemodynamic values and the myocardial oxygen extraction rate (O2ER) were evaluated at three O-A angles (45 degrees, 90 degrees, and 135 degrees) over three levels of AI (none, Sellers I-II AI, and Sellers III-IV AI). The recirculation rate, defined as the percentage of regurgitation flow to LVAD output, was calculated. Systemic flow tended to decrease with a larger O-A angle. The recirculation rate was significantly increased with a larger O-A angle (22, 23, and 31% at 45 degrees, 90 degrees, and 135 degrees in Sellers III-IV AI, respectively). Coronary artery flow was decreased at a larger O-A angle (86, 76 and 75mL/min at 45 degrees, 90 degrees, and 135 degrees in Sellers I-II AI, respectively, and 77, 67, and 56mL/min at 45 degrees, 90 degrees, and 135 degrees in Sellers III-IV AI, respectively). O2ER tended to increase with a larger O-A angle (40, 43, and 49% at 45 degrees, 90 degrees, and 135 degrees in Sellers III-IV AI, respectively). A larger O-A angle can increase the recirculation due to AI and can be disadvantageous to LVAD-AI hemodynamics and myocardial oxygen metabolism.